Arrington was right that Facebook is working on mobile with some very smart folks, but the headline overreached and MG Siegler’s followup assumes that a smart team is working on a device. Well, I think that’s horsepucky until Facebook actually ships an innovative mobile app that works on all the modern platforms. Truth is, while a Facebook-branded device would be popular it won’t get most of us to switch off of the phones we already have. Even Google demonstrated the difficulty of doing that as it launched its Nexus One and then killed that effort within a few months.

I’ve been talking with folks high up in Facebook and they deny it. But one did say “our strategy is to integrate and make all phones social, not build any specific device or integration.” Also said that the only public statement they are making on the record is the one they made in Mashable, which is why I can’t use the exec’s name.

Well, OK, now that we’re clear on that, let’s talk about what I hope Facebook is doing by looking at what’s missing from Facebook’s mobile strategy:

1. Great contact support is missing. Most people don’t even know there is ANY contact support on the iPhone app. There is. Click on “Friends” on the Facebook app’s home page and then you’ll see a button named “Sync.” But does it do much useful? Not really. It puts your friend’s photo into your phone’s contacts and it also adds a link to their Facebook profile. Does it add their phone numbers? No. Email addresses? No. Other things? No. Really lame.

2. Great photo support is missing. It’s still too hard to upload a group of photos. Heck, go to the UI in the iPhone app and figure out how to upload a photo to Facebook. It’s not that intuitive. First you have to click on “Profile” and then notice the little camera icon to do it. But what if you were thinking of uploading photos that you’ve already taken? Then clicking on a camera icon doesn’t make sense, but that’s what you need to do. Plus, I need to upload my photos to other services like SmugMug and YouTube too. Why doesn’t Facebook’s app do all of those at the same time?

2. Great video support is missing. I’d love to upload a video to Facebook AND YouTube at the same time. I can’t, at least not with the Facebook app. I don’t even think Tubemogul does that yet.

3. Location support is severely lacking. Why doesn’t Facebook’s Places hook up with other location-based services in a good way yet? They announced it but I still don’t see much integration between Facebook, Foursquare, Yelp, or Gowalla. Plus, Facebook’s main platform is still very poor when compared with other services. The one thing it does have is a TON of people on it.

4. It’s still hard to figure out how to granularly route messages to the right place. Why is it easier to post to a Facebook Page from Seesmic than it is from Facebook’s own mobile app? Why can you use Pip.io to send a status message just to your family, but I can’t figure out how to do that with Facebook’s own app? If I post something from a press conference that message needs to go to a different group of friends than my baby photos, yet Facebook treats them all the same.

5. Facebook’s own app doesn’t do anything with phone sensors. Why can we use RedLaser to point our phone at a barcode and learn where to buy that product but we can’t do anything like that on Facebook? Why can we “bump” our phones and exchange contact info on the Bump app, but not on Facebook? Why can we exchange payments on PayPal’s app by bumping phones, but not on Facebook’s app? Why can we find a new restaurant by shaking our phone on some apps, but not on Facebook? Why can we see how to walk to the bar we’re seeking on Yelp’s augmented reality feature but not on Facebook? Why can I use Runkeeper to keep track of my bike rides, but I can’t do that with Facebook’s mobile app?

6. Facebook doesn’t do anything with location proximity. At Arrington’s own conference next week DeHood will show off some new proximity-based features for you to keep in touch with your neighborhood but Facebook can’t show you who else is at the party you’re at, or who is within walking distance of you.

7. Facebook doesn’t do anything with geofences or, really, anything innovative with location that Foursquare didn’t show us two years ago. Yet just last week Footprint Feed announced support for geofencing your friends. Why doesn’t Facebook do this yet? Geofences would let you do cool location and proximity-based alerts. Imagine getting an alert anytime you got within 1,000 feet of Arrington, for instance! Or, anytime you’re close to an In-n-Out.

8. Absent on casual game mobile platform war. Facebook let Apple and Google get into the casual games market. Hell, they are even letting Microsoft and Nokia get back into that game! Why? Because Facebook doesn’t have a trusted payments system yet, and doesn’t have an app store on mobile phones. I bet that’s driving Mark Pincus over at Zynga nuts because now he has to hire three times the number of business development folks to cut deals with all these companies. Facebook could outstrip all of the other company’s efforts. Where did I learn about Angry Birds from? Not Facebook, and that should really be troubling to Facebook’s execs.

9. Lame real-time search and filtering features. Facebook is letting DataSift come into the market, which brings real-time filtering that is much more advanced than anything Facebook has done yet. Really surprising since Facebook bought FriendFeed more than a year ago (FriendFeed had great real-time search and filtering). Those kinds of features will really be important on mobile phones, due to the smaller screen available there.

10. No innovation in feed design/layout for quite some time. Facebook let Flipboard demonstrate that there’s a way to lay out Facebook feeds in a new, and more productive, way. Yet Facebook doesn’t even have an iPad app out yet. And I won’t even go into the other innovative apps and services that have hit Twitter or RSS lately like Flud, Twitter Times, Paper.li, etc.

11. Startups are kicking Facebook’s ass on info filtering. Look at the video I filmed last week with My6Sense (Part I, Part II) that shows just how far that company has come in bringing you interesting information from your Facebook and Twitter streams. Why hasn’t Facebook done that?

So, MG or Mike, tell me again why Facebook would do a device, or even an OS, BEFORE they’d fix all these things on their iPhone, Android, iPad, Blackberry, Nokia, and Windows Phone 7 apps?